Mass resonant transducer



Sept. 15, 1970 E. A. LEVIN MASS RESONANT TRANSDUCER 2 Sheets-Sheet 1 Filed Feb. 26, 1968 -PERMANENT MAGNET GAP INCREASE -'SPRING ARM DEFLECTION INCREASE- INVENTOR.

EUGENE A. LEVIN BYZ g AGENT Sept. 15, 1970 E. A. LEVIN 3,528,603

MASS RESONANT TRANSDUCER Filed Feb. 26, 1968 2 Sheets-Sheet 2 INVENTOR. EUGENE A. LEVIN w z/u AGENT United States Patent O 3,528,603 MASS RESONANT TRANSDUCER Eugene A. Levin, Oakland, Calif., assignor to SCM Corporation, a corporation of New York Filed Feb. 26, 1968, Ser. No. 708,222 Int. Cl. G06k 1/05 U.S. Cl. 234-409 Claims ABSTRACT OF THE DISCLOSURE A mass resonant device for driving a mechanical member such as a recorder element, particularly a code tape punch or a printer hammer, is disclosed. In the example given, a permanent magnet substantially comprising the mass is attracted toward and held by a fixed pole piece. A spring urges the mass away from the pole piece, and a punch is connected to the mass. Accordingly, when an electromagnet positioned and wound for opposing the flux of the permanent magnet is energized, the mass is released from the fixed pole piece and the spring accelerates the mass to a position where the attached punch effects a perforating operation.

BACKGROUND OF THE INVENTION This invention relates to high speed data recording machines and more particularly to punch-actuating means employed in tape perforating equipment.

In the communications and computer fields, devices for processing or transmitting coded information operate at ever higher speeds. It has become necessary, in the interest of high speed data transfer, to provide asynchronous mechanisms capable of printing or perforating at relatively high speeds.

One method for providing a high speed punching or printing device utilizes a mechanism in which the punch is actuated by a mass attached to a resilient member that is first stressed to a cocked position and then released. Upon such release, the mass accelerates and moves through an actuating position to effect a like movement of the punch. After the punching operation is accomplished, the member is returned and held in its cocked position by suitable means, usually by an electromagnet which must be maintained in energized condition to effect such holding. In this method the speed of the mechanism is determined by the natural frequency of the member but may operate at speeds up to and exceeding 200 cycles per second.

The devices employing an electromagnet concept for maintaining the vibrating member in a ready position inherently require standby power which in turn produces standby heat.

SUMMARY OF THE INVENTION The present invention overcomes these shortcomings by providing a permanent magnet for holding the vibrating member is stressed position without using electrical power such as required by the electromagnet of the prior art devices.

The vibrating member is connected to the punch (a print hammer or a tape feed device or other mechanical load could be substituted for purposes of this invention, but the description will be limited to a punch). The vibrating member is mainly comprised of a mass portion and a spring portion. The mass portion is substantially comprised of a permanent magnet and pole pieces which serve to retain the member in a cocked or stressed position against a fixed pole piece. When the magnet is released from the fixed pole piece and accelerated by the stressed spring portion, the moving mass of the magnet serves through the interconnectionto supply kinetic energy for perforating media.

The permanent magnet is released from the fixed pole piece by an electromagnet which, when energized, opposes the flux of the permanent magnet. The influence of the potential energy stored within the stressed spring portion accelerates the mass and associated punch pin. While the punchis approaching its fully actuated position, the electromagnet is deenergized and after the punching operation is effected, the member is restored to and retained in its cocked position by the attraction between the permanent magnet and the pole piece as the oscillating member returns near its original position.

DESCRIPTION OF THE DRAWING FIG. 1 is a right front perspective view of the vibrating member and punch shown in a cocked position.

FIG. 2 is an enlarged top plan view of the member spring portion being deflected against a stop.

FIG. 3 is a view similar to FIG. 2 but illustrating additional deflection of the spring portion when the member is in its cocked position. The deflection is exaggerated for clarity.

FIG. 4 is a force versus distance graph illustrating the comparison between the spring force curve and the permanent magnet pull force curve.

FIG. 5 is a top plan view similar to FIG. 2 but showing another embodiment of the member spring portion.

FIG. 6 is a fragmentary front elevational view of FIG. 5 illustrating the manner in which the free end of the spring portion is retained.

DESCRIPTION OF THE PREFERRED EMBODIMENT Referring to FIG. 1, a member 10 is pivotally mounted on a frame stud 11 and has: a relatively large mass 12 rigidly attached to one side of its pivot, an integral punch connecting arm 14 and an integral spring arm 16. The locations shown for the mass, punch arm and spring arm relative to the pivot are not material to the invention, the inventive concept would apply equally well were the punch connected on the same side of the pivot as the mass. A punch 17 is connected to arm 14 and guided in appropriate guide plates 18 and 20 for reciprocating movement in response to oscillation of member 10.

Punch 17 is substantially tangential to and is connected to arm 14 by means of a peripheral slot 28 that cradles a substantially circular end portion 30 of the connecting arm. Guide plate 18 is rigidly mounted by screws 32 to an upstanding portion 34 of a support plate 36 which is in turn rigidly mounted to a frame plate 38 by screws 40. Guide plate 20 is rigidly mounted opposite a punch die 42 by screws 44 while the die 42 is in turn rigidly mounted by screws (not shown) to the support plate 3 6.

Mass 12 comprises a permanent magnet 22 and pole piece plates 46 which normally pull toward a pole piece 24 to retain member 10 and punch 17 in a cocked posi-,

tion as shown. Spring arm 16 is bifurcated at its terminal end for engagement with a pin 58. Because mass 12 is attracted to the pole piece 24 the spring arm is strained by virtue of its engagement with pin 58.

Member 10 remains in this cocked position until electromagnet 26 is energized. Electromagnet 26 is positioned in fixed pole piece 24 and is wound so that when energized it provides a repelling force at least equal to the attractive force of the permanent magnet for the pole piece.

When electromagnet 26 is energized, mass 12 is released and potential energy stored within spring arm 16 is converted to kinetic energy, mass 12 being angularly accelerated clockwise in a punch actuating direction as a result. As the member accelerates, the kinetic energy of the member increases and thereby aids in movement of arm .14 and punch 17 through the punching position. Reciprocating movement of punch pin 17 acts in conven tional fashion to punch holes in a paper tape 68, for example.

Permanent magnet 22 is rigidly clamped between a pair of magnetic plates 46 by means of nonmagnetic screws 48 and nonmagnetic spacers 50. The screws 48 at the left end of mass portion 12 also extend through the right end of member lever 52 which is centrally located between the plates 46 by appropriate spacers (not shown) above and below the lever 52 and about the screws 48.

An elastomer bumper 54 is fastened (as by cementing) to the side of the permanent magnet 22 and acts to cushion the shock when the permanent magnet plates 46 contact the fixed pole piece 24 during operation.

The spring arm 16 has a bifurcated terminal end 56 straddling pin 58, a pin mounted adjustably, but rigid in any adjusted position. Spring arm 16 is in its normal relaxed position when mass portion 12 is at a distance from magnetic pole piece 24; however when mass portion 12 is attracted toward pole piece 24, the spring arm bows concave upward as shown in FIG. 2. As the motion continues, the convex side of the arm then contacts a second adjustable pin 60 as shown in FIG. 2. The purpose of pin 60 is to provide a variable spring rate, as described below.

After the spring arm has contacted pin 60, further movement of the mass portion toward the pole piece causes spring arm portion 62 (FIG. 3) to eventually bow in a convex upward direction opposite to spring arm portion 64 which bows ever more strongly in a concave upward direction.

When mass portion 12 has moved to its fully attracted position against fixed pole piece 24, spring arm 16 is stiffer (FIG. 3) than it was when it initially moved from its relaxed (dotted line) position 66 (FIG. 2) to its full line position shown in FIG. 2. Consequently, the spring arm possesses different spring rates before and after it contacts pin 60 as it is being fully stressed, the greater of which rates first influences member when the force of permanent magnet 22 is rendered ineffective by electromagnet 26.

Assume now that electromagnet 26 is energized to overcome the magnetic force of permanent magnet 22. When this occurs, the potential energy stored within spring arm 16 accelerates member 10 in a clockwise direction about pin 1.1 driving punch 17 toward code tape 68.

Tape 68, positioned between punch guide plate 20 and punch die 42, is conventionally advanced to the right in accordance with the punch cycle by any suitable cyclically driven feed wheel 70. The mass resonant transducer of the invention may also be used to power such a feed wheel by means of a pawl and ratchet.

As punch 17 is driven by momentum of the mass through the tape 68 and into its appropriate punch hole in punch die 42, the electromagnet is deenergized and the momentum of member 10 causes spring arm 16 to bow slightly beyond its normal relaxed position in the direction opposite the position shown in FIG. 2. In so doing, the kinetic energy is converted into potential energy stored in spring arm 16 which will then accelerate member 10 in the return direction. This acceleration assists the attraction of permanent magnet 22 in returning member 10 back toward pole piece 24.

The different spring rates which may be generated in spring arm 16 as it is fully stressed are used to advantage in that these rates may be designed to match the permanent magnet pull and the spring-force curves more closely.

More specifically and with reference to FIG. 4, a permanent magnet force-gap curve 72 is, by nature, parabolic in shape whereas the force-deflection curve 74, 76

for the spring arm without employment of the pin 60 is linear or straight. By providing pin 60 in the normal path of movement of the spring arm when it is being stressed, the different spring rate curves 74 and 78 when plotted on a graph together with permanent magnet pull curve 72 more closely match the parabolic shape of curve 72 than does the spring arm single constant spring rate curve 74, 76 obtained with pin 60 absent.

' The force required to initially deflect spring arm 16 is small at a distance where the permanent magnet force is weak, whereas the force required to deflect the spring arm after it contacts the pin 60 is great but at that position the permanent magnet force is strong. Further, be cause the force of the magnet as it approaches the pole piece increases at a more rapid rate than does the potential energy force being stored within the spring arm, use of pin 60 allows a greater potential energy force to be stored within the spring arm during the last portion of permanent magnet movement.

This offers two advantages in that it provides for more balance between the permanent magnet and spring arm forces during the return stroke thereby providing a quieter operating mechanism and it also provides a greater potential energy force in the spring arm to initially accelerate the member when the electromagnet is energized thereby providing greater operating speed to the mechanism.

Referring again to FIG. 1, pin 58 straddled by the bifurcated spring arm end 56 is rigidly and eccentrically mounted on a post 80 which is pivotally mounted to the frame plate 38 by a screw (not shown) that extends up through the plate and is threaded into the base of the post 80.

The pin 60 is rigidly mounted to a plate 82 which is in turn mounted to the frame plate 38 for adjustment by a screw 84 which extends through the plate 82 and a frame plate elongated slot 86 and is threaded into a clamping bar (not shown) on the under side of the frame plate 38.

It can now be seen that by adjusting the post 80 circularly about its pivot and/or the plate 82 longitudinally of the slot 86, the aforementioned different spring rates of the spring arm will appropriately increase or decrease. This in turn increases or decreases the spring arm vibrating frequency and therefore the operating speed of the mechanism.

Referring now to FIGS. 5 and 6, in which another spring arm embodiment is shown, spring arm 16 is cradled near its terminal end by a pair of pins 88 which are rigidly mounted to a post 90. The post 90 is in turn slidably mounted in frame plate 38 by means of a screw 92 that extends through a frame plate elongated slot 94- and is threaded into the base of post 90. By adjusting post 90 longitudinally of slot 94, the same previously mentioned spring rate adjustability is achieved as with the eccentric-pin equipped adjustable post 80 shown in FIG. 1.

The spring arm 16 of both embodiments (FIGS. 2 and 5) is tapered toward its terminal end in order to provide the spring arm with uniform strength throughout its length.

The punch 17 is only one of a plurality of such punches that are guided within the guide plates 18 and 20 and are driven by respective members such as the member 10. The members are alternately stacked on opposite sides of the guide plates, each member operating in the same manner as does member 10 and in cooperation with a respective electromagnet.

The electromagnets are energized by any suitable signal receiving distributor wherein the incoming code Signals may be translated and selectively applied to the appropriate electromagnets.

Thus, the present invention herein just described provides a tape perforating mechanism which is capable of high speed operation by vibrating a punch connected mass. Other advantages are evident in realizing that the present invention is asynchronous in operation, requires no standby power, has a minimum number of parts, and produces no standby noise or heat.

This invention may be embodied in other specific forms without departing from the spirit or essential characteristics thereof. The present embodiments are therefore to be considered in all respects as illustrative and not restrictive, the scope of the invention being indicated by the appended claims rather than by the foregoing description and all changes which come within the meaning and range of equivalency of the claims are therefore intended to be embraced therein.

What is claimed and desired to be secured by Letters Patent is:

1. A mass resonant transducer for operating a utilization device (17, 42, 68, 70) comprising:

(a) an actuating lever pivotally mounted on a fixed framework (38) said lever having a permanent magnet (22) fixed thereto, and being connected to said utilization device,

(b) means (16, 58, 80) for yieldably urging said lever in a first direction in which it is operable to actuate said device,

(c) a pole piece (24) fixed on said framework in such a position that the permanent magnet is attracted thereto against the urgency of said yieldable means, and thereby causing potential energy to be stored in said yieldable means; and

(d) an electromagnet (26) in the pole piece, which when energized momentarily, opposes the flux of the permanent magnet thus releasing said actuating lever from the attraction of the pole piece and causing operation of said utilization device.

2. A mass resonant transducer as defined in claim 1, wherein said utilization device is a punch (17, 42, 68), said actuating lever (10) being connected to a reciprocable punch pin (17), and said yieldable means (16, 58, 80) urging said lever in a first direction in which the lever is operable to actuate said punch pin to a punching position.

3. A punch as defined in claim 1 in which:

(a) said lever comprises a first arm (52) having the permanent magnet (22) fixed thereto and a second arm (14) connected to the punch pin (17), and

(b) the yieldable means comprises a third arm (16) integral with said lever (10), said third arm having an end remote from said lever and held by a stop (58).

4. A punch as defined in claim 3 in which said stop comprises a pair of stop pins (88, FIG. 5) provided on opposite sides of the third arm (16).

5. A punch as defined in claim 3 in which the end of the third arm (16) is held by an adjustable stop (58, 80).

6. A punch as defined in claim 3 in which the third arm (16) is tapered down from a point of attachment to said lever to the terminal end thereof.

7. A punch as defined in claim 3, wherein a second stop pin is carried by said framework and lies in the path of movement of said third arm during the movement of said lever under control of the permanent magnet (22) to thereby cause said arm to yield at a variable rate.

8. A punch as defined in claim 7 in which the second stop pin (60) is adjustable to different stop positions (82, 84, 86) along the arm to change the spring rate thereof.

9. A mass resonant transducer as defined in claim 2 in which the yieldable means (16, 58, is integral with the actuating lever (10).

10. A mass resonant transducer as defined in claim 1 in which the means (16, 58, 80) for yieldably urging said lever in a first direction, is integral with the actuating lever (10).

References Cited UNITED STATES PATENTS 2,999,632 9/ 1961 Tailleur. 3,096,015 7/ 1963 Bradbury 234-107 3,198,428 8/1965 Busch 234-119 OTHER REFERENCES IBM Technical Disclosure Bulletin, vol. 7, No. 2, page 137, July 1964.

WILLIAM S. LAWSON, Primary Examiner US. Cl. X.R. 

